This invention relates to tufting machines, and more particularly to a looper apparatus for a multiple-needle tufting machine adapted to form loop pile and cut pile in the same row of stitching.
In multiple-needle tufting machines having conventional gauges of 1/4" or greater, loop pile and cut pile have been formed in the same row of stitching by looper apparatus, such as that disclosed in the Card U.S. Pat. No. 3,084,645, issued Apr. 9, 1963.
In the prior Card patent, the looper apparatus includes a hook having a smooth, pointed bill extending in the direction opposite from the direction of the fabric feed. A looper clip is fixed to the needle side of each hook and extends along, but is laterally spaced from and below the lower or bottom edge of, the hook, and then terminates in a free end or clamp portion biased into engagement against the free or pointed end portion of the hook. In the prior Card patent, the speed of the yarn fed to the needles is selectively controlled by a pattern control mechanism. Normal lengths of yarn are fed to the needles for making a normal-length loop pile which is secured and held upon the bill of the looper apparatus and subsequently cut by a knife to form a normal-length cut-pile tuft. On the other hand, when the pattern control mechanism starves the yarn feed, tension is applied to the yarn caught on the hook. As the hook retracts, the yarn forces the clamping end of the looper clip way from the bill so that the loop is released and shortened, but is not cut, to thereby form a shorter uncut pile loop.
However, since the trend in the tufting industry is to employ more narrow needle gauges for forming tufted fabrics, such as carpet, the hooks, looper clips and knives become more crowded, as the gauge of the needles is reduced. Where the gauge is reduced to 3/16 of an inch, the knives must be set with more care, thereby requiring more time, so that the looper clips will not interfere with the knives.
When the gauge is reduced to 5/32 of an inch, the setting of knives becomes extremely critical. When the gauge is reduced to 1/8 of an inch, production of tufting fabrics including loop pile and cut pile in the same row of stitching formed by adjacent hooks, knives and looper clips, becomes practically impossible.
Where the gauge is so narrow, the looper clip of one looper interferes with the knife of the adjacent looper.